摘要
【目的】研究聚乙二醇6000(PEG 6000)模拟干旱对铁皮石斛Dendrobium candidum生理和叶绿素荧光特性的影响,为铁皮石斛的品种选育、产业化栽培和近野生栽培等提供参考。【方法】以铁皮石斛‘晶品1号’D.candidum‘Jingpin No.1’幼苗为实验材料,通过不同质量分数PEG 6000(5%、10%、20%、30%)模拟干旱胁迫处理铁皮石斛幼苗,观察铁皮石斛幼苗茎段和叶片细胞结构,并检测铁皮石斛叶片过氧化物酶(POD)、过氧化氢酶(CAT)活性及丙二醛(MDA)质量摩尔浓度、可溶性糖质量分数、可溶性蛋白质量分数、叶绿素质量分数及叶绿素荧光参数的动态变化。【结果】①高质量分数PEG 6000(20%-30%)处理后铁皮石斛茎段和叶片细胞内叶绿素质量分数减少。②PEG 6000模拟干旱胁迫处理对铁皮石斛幼苗可溶性糖和可溶性蛋白、MDA、POD和CAT有显著影响(P<0.05)。可溶性糖质量分数随着PEG 6000质量分数的增加和处理时间的延长均呈上升趋势,到第12天时达最高值;可溶性蛋白则呈下降趋势;MDA质量摩尔浓度、POD活性和CAT活性随着PEG 6000质量分数的增加呈先上升后下降的趋势,在PEG 6000为20%时达到峰值。③PEG 6000模拟干旱处理对铁皮石斛幼苗最大光化学效率(F_(v)/F_(m))、光合效率(α)、电子传递速度(ETR)、光化学猝灭系数(q_(P))和非化学猝灭系数(qNP)等叶绿素荧光参数有显著的影响(P<0.05)。随着PEG 6000胁迫处理时间的延长和PEG 6000质量分数的增加,α、ETR、F_(v)/F_(m)和q_(P)均呈显著下降趋势(P<0.05);而qNP则呈先上升后下降的趋势。【结论】20%PEG 6000处理12 d可用作铁皮石斛抗干旱品种的筛选,铁皮石斛幼苗可通过增加可溶性糖质量分数,减少可溶性蛋白质量分数,提高POD和CAT活性等防御酶活性抵抗和适应一定程度的干旱胁迫;铁皮石斛幼苗的最大光能转换效率降低,光合系统Ⅱ(PSⅡ)受到胁迫损伤,严重影响铁皮石斛幼苗
[Objective]The objective is to study the effects of PEG 6000 simulated drought on physiological and chlorophyll fluorescence characteristics of Dendrobium candidum,so as to provide reference for variety selection,industrial cultivation,and near wild cultivation of D.candidum.[Method]The seedlings of D.candidum‘Jingpin No.1’were used as experimental materials and treated with PEG 6000 at different concentrations to simulate drought stress.The stem segment and leaf cell structure of D.candidum seedlings were observed,and the dynamic changes of peroxidase(POD),catalase(CAT)activity,malondialdehyde(MDA),soluble sugar,soluble protein,chlorophyll content and chlorophyll fluorescence parameters in D.candidum leaves were detected.[Result](1)The content of chlorophyll in the stem and leaf cells of D.candidum decreased after treatment with high concentration of PEG 6000(20%−30%).(2)PEG 6000 simulated drought stress significantly affected the content of soluble sugar and protein,MDA,POD and CAT activity of D.candidum seedlings.The soluble sugar content increased with the increase of PEG 6000 concentration and the extension of treatment time,reaching its highest value on the 12th day,while the soluble protein showed a downward trend.MDA content,POD and CAT activity increased first and then decreased with the increase of PEG 6000 concentration,reaching the peak at a PEG 6000 concentration of 20%.(3)PEG 6000 simulated drought treatment of D.candidum seedlings significantly affected chlorophyll fluorescence parameters such as maximum photochemical efficiency(F_(v)/F_(m)),photosynthetic efficiency(α),electron transfer rate(ETR),photochemical quenching coefficient(q_(P))and non-chemical quenching coefficient(qNP).With the extension of PEG 6000 stress treatment time and the increase of PEG 6000 concentration,α,ETR,F_(v)/F_(m) and q_(P) showed a significant downward trend,while qNP showed a trend of first increasing and then decreasing.[Conclusion]20%PEG 6000 treatment for 12 days can be used as a method for screening droug
作者
冯蕊
周琪
吴令上
朱玉球
高燕会
FENG Rui;ZHOU Qi;WU Lingshang;ZHU Yuqiu;GAO Yanhui(State Key Laboratory of Subtropical Silviculture,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China)
出处
《浙江农林大学学报》
CAS
CSCD
北大核心
2024年第1期132-144,共13页
Journal of Zhejiang A&F University
基金
国家级大学生创新创业训练计划(201910341008)
浙江省农业新品种选育重大科技专项(2021C02074)。
关键词
铁皮石斛
干旱胁迫
生理生化指标
叶绿素荧光参数
聚乙二醇
Dendrobium candidum
drought stress
physiology and biochemistry indicators
chlorophyll fluorescence parameters
PEG
